Benzanthracene compound and organic electroluminescence device using the same

ABSTRACT

A compound having the following structure as at least a part thereof: 
     
       
         
         
             
             
         
       
     
     wherein FA and FA′ are independently a substituted or unsubstituted hydrocarbon aromatic ring or hetero atom-containing aromatic ring, and at least one of FA and FA′ is the hetero atom-containing aromatic ring.

TECHNICAL FIELD

The invention relates to a novel benzanthracene compound which is usefulas an emitting material for an organic electroluminescence device, andan organic electroluminescence device using the same.

BACKGROUND ART

An organic electroluminescence (EL) device is a self-emission deviceutilizing the principle that a fluorescent compound emits light by therecombination energy of holes injected from an anode and electronsinjected from a cathode when an electric field is impressed.

An organic EL device has made a remarkable progress. In addition, sincean organic EL device has characteristics such as low voltage driving,high luminance, variety in emission wavelength, high response andcapability of fabricating a thin and lightweight emitting device, itsapplication to a wide range of fields is expected.

Emission materials used in an organic EL device have conventionally beenstudied actively since they influence largely the color of light emittedby a device or on emission life.

As the emission material, a material emitting light by itself and a hostmaterial containing a small amount of a dopant are known. Furthermore,it has been studied that triplet energy is used for emission by using aphosphorescent compound as an emission material instead of a fluorescentemitting material. By using such various emission materials, emission ina visible range from blue to red can be obtained.

As examples of the emitting material, Patent Documents 1 and 2 disclosebenzanthracene derivatives. However, organic EL devices using thesebenzanthracene derivatives have short half life and are inferior inchromaticity.

[Patent Document 1] JP-A-2000-178548

[Patent Document 2] JP-A-2007-277113

An object of the invention is to provide a novel emitting material andan organic EL device using the emitting material.

DISCLOSURE OF THE INVENTION

According to the invention, the following compound, organic EL deviceand the like are provided.

1. A compound having the following structure as at least a part:

wherein

FA and FA′ are independently a substituted or unsubstituted hydrocarbonaromatic ring or hetero atom-containing aromatic ring, and at least oneof FA and FA′ is the hetero atom-containing aromatic ring.

2. The compound according to 1, which has one of the followingstructures as at least a part thereof:

wherein

X is oxygen, sulfur or N—R wherein R is a hydrocarbon group, and

FA and FA′ are independently a substituted or unsubstituted hydrocarbonaromatic ring or hetero atom-containing aromatic ring.

3. An emitting material comprising the compound according to 1 or 2.4. An organic electroluminescence device which comprises:

an anode, a cathode, and one or more organic thin film layers includingan emitting layer, which are between the anode and the cathode,

wherein at least one layer of the organic thin film layers comprises thecompound according to 1 or 2.

5. The organic electroluminescence device according to 4, wherein thelayer comprising the compound further comprises at least one of aphosphorescent dopant and a fluorescent dopant.6. The organic electroluminescence device according to 5, wherein thefluorescent dopant is at least one of arylamine compounds andstyrylamine compounds.7. The organic electroluminescence device according to 5 or 6, whereinthe phosphorescent dopant is a metal complex.

According to the invention, a novel compound and an organic EL deviceusing the compound can be provided.

The organic EL device using the compound of the invention is superior inpurity and half life.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of the organic EL deviceaccording to one embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The benzanthracene compound of the invention is a compound having thefollowing structure as at least a part:

wherein FA and FA′ are independently a substituted or unsubstitutedhydrocarbon aromatic ring or hetero atom-containing aromatic ring, andat least one of FA and FA′ is the hetero atom-containing aromatic ring.

The benzanthracene compound of the invention contains the abovestructure as a part or a whole. For example, the benzanthracene compoundof the invention may be a compound in which the above structure isfurther substituted, and may be the structure itself.

Examples of the hetero atom-containing aromatic ring include furan,thiophene, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene,carbazole, benzocarbazole, dibenzocarbazole, indole, isoindole,isobenzofuran, quinoline, isoquinoline, phenanthroline, acridine,1,7-phenanthroline, 1,8-phenanthroline, 1,9-phenanthroline,2,9-phenanthroline, 2,8-phenanthroline, 2,7-phenanthroline, phenazine,phenothiazine, phenoxazine, oxazoline, oxadiazoline, cinnoline,quinoxaline, phthalazine, phenanthridine, indolizine, quinazoline,1H-indazole, phenoxathiine, thianthrene, furazan, indoline, isoindoline,chromane and isochromane.

Preferable examples of the hetero atom-containing aromatic ring includefuran, benzofuran, dibenzofuran, thiophene, benzothiophene,dibenzothiophene, indole and carbazole. The hetero atom-containingaromatic ring is preferably a hetero atom-containing fused ring, and isfor example benzofuran, dibenzofuran, benzothiophene ordibenzothiophene.

A preferable benzanthracene compound is a compound having one of thefollowing structures as at least a part thereof:

wherein X is oxygen, sulfur or N—R wherein R is a hydrocarbon group, andFA and FA′ are independently a substituted or unsubstituted hydrocarbonaromatic ring or hetero atom-containing aromatic ring.

Examples of the hydrocarbon group R include

a methyl group, ethyl group, propyl group, isopropyl group, phenylgroup, naphthyl group, biphenyl group, tolyl group and xylyl group.

Examples of the hydrocarbon aromatic ring include a phenyl group,1-naphthyl group, 2-naphthyl group, 1-anthranyl group, 2-anthranylgroup, 9-anthranyl group, 1-phenanthryl group, 9-phenanthryl group,1-pyrenyl group, 2-pyrenyl group, 1-chrysenyl group, 2-chrysenyl group,3-chrysenyl group, 4-chrysenyl group, 5-chrysenyl group and 6-chrysenylgroup.

The hydrocarbon aromatic ring is preferably a hydrocarbon fused ring,and an example of the hydrocarbon fused ring is preferably a combinationof 2 to 4 benzene rings, more preferably a combination of 2 to 3 benzenerings, and particularly preferably naphthyl.

Substituents of the structures of the above formulas include asubstituted or unsubstituted alkyl group (one having preferably 1 to 20,more preferably 1 to 12 and particularly preferably 1 to 8 carbon atoms,the specific examples of which include methyl, ethyl, isopropyl,t-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl andcyclohexyl), a substituted or unsubstituted alkenyl group (one havingpreferably 2 to 20, more preferably 2 to 12 and particularly preferably2 to 8 carbon atoms, the specific examples of which include vinyl,allyl, 2-butenyl and 3-pentenyl), a substituted or unsubstituted alkynylgroup (one having preferably 2 to 20, more preferably 2 to 12 andparticularly preferably 2 to 8 carbon atoms, the specific examples ofwhich include propynyl and 3-pentynyl), a substituted or unsubstitutedaryl group (one having preferably 6 to 60, more preferably 6 to 20carbon atoms, the specific examples of which include phenyl, naphthyl,anthracenyl, phenanthryl, benzanthracenyl, chrysenyl and pyrenyl), asubstituted or unsubstituted amino group (one having preferably 0 to 20,more preferably 0 to 12 and particularly preferably 0 to 6 carbon atoms,the specific examples of which include amino, methylamino,dimethylamino, diethylamino, diphenylamino and dibenzylamino), asubstituted or unsubstituted alkoxy group (one having preferably 1 to20, more preferably 1 to 12 and particularly preferably 1 to 8 carbonatoms, the specific examples of which include methoxy, ethoxy andbuthoxy), a substituted or unsubstituted aryloxy group (one havingpreferably 6 to 20, more preferably 6 to 16 and particularly preferably6 to 12 carbon atoms, the specific examples of which include phenyloxyand 2-naphthyloxy), an acyl group (one having preferably 1 to 20, morepreferably 1 to 16 and particularly preferably 1 to 12 carbon atoms, thespecific examples of which include acetyl, benzoyl, formyl andpivaloyl), a substituted or unsubstituted alkoxycarbonyl group (onehaving preferably 2 to 20, more preferably 2 to 16 and particularlypreferably 2 to 12 carbon atoms, the specific examples of which includemethoxycarbonyl and ethoxycarbonyl), a substituted or unsubstitutedaryloxycarbonyl group (one having preferably 7 to 20, more preferably 7to 16 and particularly preferably 7 to 10 carbon atoms, the specificexamples of which include phenyloxycarbonyl), a substituted orunsubstituted acyloxy group (one having preferably 2 to 20, morepreferably 2 to 16 and particularly preferably 2 to 10 carbon atoms, thespecific examples of which include acetoxy and benzoyloxy), asubstituted or unsubstituted acylamino group (one having preferably 2 to20, more preferably 2 to 16 and particularly preferably 2 to 10 carbonatoms, the specific examples of which include acetylamino andbenzoylamino), a substituted or unsubstituted alkoxycarbonylamino group(one having preferably 2 to 20, more preferably 2 to 16 and particularlypreferably 2 to 12 carbon atoms, the specific examples of which includemethoxycarbonylamino), an aryloxycarbonylamino group (one havingpreferably 7 to 20, more preferably 7 to 16 and particularly preferably7 to 12 carbon atoms, the specific examples of which includephenyloxycarbonylamino), a substituted or unsubstituted sulfonylaminogroup (one having preferably 1 to 20, more preferably 1 to 16 andparticularly preferably 1 to 12 carbon atoms, the specific examples ofwhich include methanesulfonylamino and benzenesulfonylamino), asubstituted or unsubstituted sulfamoyl group (one having preferably 0 to20, more preferably 0 to 16 and particularly preferably 0 to 12 carbonatoms, the specific examples of which include sulfamoyl,methylsulfamoyl, dimethylsulfamoyl and phenylsulfamoyl), a substitutedor unsubstituted carbamoyl group (one having preferably 1 to 20, morepreferably 1 to 16 and particularly preferably 1 to 12 carbon atoms, thespecific examples of which include carbamoyl, methylcarbamoyl,diethylcarbamoyl and phenylcarbamoyl), a substituted or unsubstitutedalkylthio group (one having preferably 1 to 20, more preferably 1 to 16and particularly preferably 1 to 12 carbon atoms, the specific examplesof which include methylthio and ethylthio), a substituted orunsubstituted arylthio group (one having preferably 6 to 20, morepreferably 6 to 16 and particularly preferably 6 to 12 carbon atoms, thespecific examples of which include phenylthio), a substituted orunsubstituted sulfonyl group (one having preferably 1 to 20, morepreferably 1 to 16 and particularly preferably 1 to 12 carbon atoms, thespecific examples of which include mesyl and tosyl), a substituted orunsubstituted sulfinyl group (one having preferably 1 to 20, morepreferably 1 to 16 and particularly preferably 1 to 12 carbon atoms, thespecific examples of which include methanesulfinyl andbenezenesulfinyl), a substituted or unsubstituted ureido group (onehaving preferably 1 to 20, more preferably 1 to 16 and particularlypreferably 1 to 12 carbon atoms, the specific examples of which includeureido, methylureido and phenylureido), a substituted or unsubstitutedphosphoric amide group (one having preferably 1 to 20, more preferably 1to 16 and particularly preferably 1 to 12 carbon atoms, the specificexamples of which include diethylphosphoric amide and phenylphosphoricamide), a hydroxyl group, a mercapto group, a halogen atom (for example,a fluorine atom, a chlorine atom, a bromine atom and an iodine atom), acyano group, a sulfo group, a carboxy group, a nitro group, a hydroxamicacid group, a sulfino group, a hydrazino group, an imino group, aheterocyclic group (one having preferably 1 to 30 and more preferably 1to 12 carbon atoms and containing, as the hetero atom, a nitrogen atom,an oxygen atom and a sulfur atom, for example, the specific examples ofwhich include imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl,morpholino, benzoxazolyl, benzimidazoyl, benzothiazolyl and carbazolyl),and a silyl group (one having preferably 3 to 40, more preferably 3 to30 and particularly preferably 3 to 24 carbon atoms, the examples ofwhich include trimethylsilyl and triphenylsilyl). These substituents maybe further substituted. If there are two or more substituents, thesesubstituents may be the same or different. If possible, they may becombined each other to form a ring.

Examples of preferable substituents include methyl, ethyl, propyl,isopropyl, butyl, sec-butyl, tert-butyl, cyclohexyl, phenyl, 1-naphthyl,2-naphthyl, trimethylsilyl and triphenylsilyl.

Examples of the benzanthracene compound are given below.

The benzanthracene compound can be used as an emitting material for anorganic EL device.

The organic EL device of the invention comprises an anode, a cathode andone or more organic thin layers comprising an emitting layer between theanode and the cathode, and at least one of the organic thin layerscomprise the above-mentioned compound.

A layer containing the above-mentioned compound may contain at least oneof a phosphorescent dopant and a fluorescent dopant. The layer canfunction as a phosphorescent emitting layer and fluorescent emittinglayer by containing such dopants.

Representative configurations of the organic EL device of the inventioncan be given below.

(1) Anode/emitting layer/cathode(2) Anode/hole-injecting layer/emitting layer/cathode(3) Anode/emitting layer/electron-injecting layer/cathode(4) Anode/hole-injecting layer/emitting layer/electron-injectinglayer/cathode(5) Anode/organic semiconductor layer/emitting layer/cathode(6) Anode/organic semiconductor layer/electron-barrier layer/emittinglayer/cathode(7) Anode/organic semiconductor layer/emitting layer/adhesion-improvinglayer/cathode(8) Anode/hole-injecting layer/hole-transporting layer/emittinglayer/electron-injecting layer/cathode(9) Anode/insulating layer/emitting layer/insulating layer/cathode(10) Anode/inorganic semiconductor layer/insulating layer/emittinglayer/insulating layer/cathode(11) Anode/organic semiconductor layer/insulating layer/emittinglayer/insulating layer/cathode(12) Anode/insulating layer/hole-injecting layer/hole-transportinglayer/emitting layer/insulating layer/cathode(13) Anode/insulating layer/hole-injecting layer/hole-transportinglayer/emitting layer/electron-injecting layer/cathode

The representative examples of the configuration of the organic ELdevice of the invention are, however, not limited to the above. Ofthese, the configuration (8) is preferable.

In the organic EL device of the invention, although the compound of theinvention may be used in any of the above-mentioned organic layers, thecompound is preferably contained in an emitting region, particularlypreferably an emitting layer. The content of the compound is preferably30 to 100 wt %. When the compound is used in another layer, it may beused either singly or in mixture with another compound.

The configuration (8) is shown in FIG. 1. This organic EL devicecomprises a cathode 20, an anode 10, and a hole-injecting layer 30, ahole-transporting layer 32, an emitting layer 34 and anelectron-injecting layer 36 between the anode and the cathode. Thehole-injecting layer 30, the hole-transporting layer 32, the emittinglayer 34 and the electron-injecting layer 36 correspond to the pluralityof organic thin film layers. At least one of these organic thin filmlayers 30, 32, 34 and 36 comprises the benzanthracene compound.

Each member of the organic EL device will be explained below.

The organic EL device is normally formed on a substrate. The substratesupports the organic EL device. It is preferable to use a smoothsubstrate. If light is outcoupled through the substrate, it is preferredthat the substrate be a transparent substrate with a transmission tovisible rays with a wavelength of 400 to 700 nm of 50% or more.

As such tranparent substrate, a glass plate, a synthetic resin plate orthe like are preferably used. Examples of the glass plate include platesof soda-lime glass, barium/strontium-containing glass, lead glass,aluminosilicate glass, borosilicate glass, barium borosilicate glass,quartz, or the like. Examples of the synthetic resin plates includeplates of a polycarbonate resin, an acrylic resin, a polyethyleneterephthalate resin, a polyether sulfide resin, a polysulfone resin, orthe like.

It is effective that the anode injects holes to the hole-injectinglayer, the hole-transporting layer or the emitting layer and has a workfunction of 4.5 eV or more. Specific examples of the anode materialinclude indium tin oxide (ITO), a mixture of indium oxide and zincoxide, a mixture of ITO and cerium oxide, a mixture of IZO and ceriumoxide, a mixture of indium oxide and cerium oxide, a mixture of zincoxide and aluminum oxide (AZO), tin oxide (NESA), gold, silver, platinumand copper.

The anode can be formed from these electrode materials by a vapordeposition method, a sputtering method or the like.

In the case where emission from the emitting layer is outcoupled throughthe anode, the transmittance of the anode to the emission is preferablymore than 10%. The sheet resistance of the anode is preferably severalhundred Ω/□ or less. The film thickness of the anode, which variesdepending upon the material thereof, is usually from 10 nm to 1 μm,preferably from 10 to 200 nm.

The emitting layer has the following functions.

(i) Injection function: function of allowing injection of holes from theanode or hole-injecting layer and injection of electrons from thecathode or electron-injecting layer upon application of an electricfield(ii) Transporting function: function of moving injected carriers(electrons and holes) due to the force of an electric field(iii) Emission function: function of recombining electons and holes toemit light

As the method of forming the emitting layer, a known method such asdeposition, spin coating, or an LB method may be applied. It ispreferable that the emitting layer be a molecular deposition film. Themolecular deposition film is a film formed by deposition of a materialcompound in a gas phase, or by solidification of a material compound inthe form of a solution or in a liquid phase. The molecular depositionfilm can be usually distinguished from a thin film (molecularaccumulation film) formed using the LB method by the difference inaggregation structure or higher order structure or the difference infunction due to the difference in structure.

The emitting layer may also be formed by dissolving a binder such as aresin and a material compound in a solvent to obtain a solution, andforming a thin film from the solution by spin coating or the like.

Examples of the emission material or the dopant material which can beused in the emitting layer include anthracene, naphthalene,phenanthrene, pyrene, tetracene, coronene, chrysene, fluoresceine,perylene, phthaloperylene, naphthaloperylene, perynone, phthaloperynone,naphthaloperynone, diphenylbutadiene, tetraphenylbutadiene, coumarin,oxadizole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine,cyclopentadiene, quinoline metal complex, aminoquinoline metal complex,benzoquinoline metal complex, imine, diphenylethylene, vinylanthracene,diaminocarbazole, pyrane, thiopyran, polymethine, merocyanine, imidazolechelated oxynoid compound, quinacridon, rubrene, derivatives thereof,and fluorescent dyes, but they are not limited thereto.

Specific examples of the host material which can be used together in theemitting layer include compounds shown by the following formulas (i) to(ix):

Asymmetrical anthracene represented by the following formula (i):

wherein Ar⁰⁰¹ is a substituted or unsubstituted fused aromatic grouphaving 10 to 50 carbon atoms that form a ring (hereinafter referred toas “ring carbon atoms”),

Ar⁰⁰² is a substituted or unsubstituted aromatic group having 6 to 50ring carbon atoms,

X⁰⁰¹ to X⁰⁰³ are independently a substituted or unsubstituted aromaticgroup having 6 to 50 ring carbon atoms, a substituted or unsubstitutedaromatic heterocyclic group having 5 to 50 atoms that form a ring(hereinafter referred to as “ring atoms”), a substituted orunsubstituted alkyl group having 1 to 50 carbon atoms, a substituted orunsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted orunsubstituted aralkyl group having 6 to 50 carbon atoms, a substitutedor unsubstituted aryloxy group having 5 to 50 ring atoms, a substitutedor unsubstituted arylthio group having 5 to 50 ring atoms, a substitutedor unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, acarboxyl group, a halogen atom, a cyano group, a nitro group and ahydroxy group,

a, b and c are each an integer of 0 to 4.

n is an integer of 1 to 3, and when n is two or more, groups in the [ ]may be the same or different.

Asymmetrical monoanthracene derivatives represented by the followingformula (ii):

wherein Ar⁰⁰³ and Ar⁰⁰⁴ are independently are a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms,

m and n are each an integer of 1 to 4,

provided that in the case where m=n=1 and Ar⁰⁰³ and Ar⁰⁰⁴ aresymmetrically bonded to the benzene rings, Ar⁰⁰³ and Ar⁰⁰⁴ are not thesame, and in the case where m or n is an integer of 2 to 4, m isdifferent from n,

R⁰⁰¹ to R⁰¹⁰ are independently are a hydrogen atom, a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms, asubstituted or unsubstituted aromatic heterocyclic group having 5 to 50ring atoms, a substituted or unsubstituted alkyl group having 1 to 50carbon atoms, a substituted or unsubstituted cycloalkyl group, asubstituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, asubstituted or unsubstituted aralkyl group having 6 to 50 carbon atoms,a substituted or unsubstituted aryloxy group having 5 to 50 ring atoms,a substituted or unsubstituted arylthio group having 5 to 50 ring atoms,a substituted or unsubstituted alkoxycarbonyl group having 1 to 50carbon atoms, a substituted or unsubstituted silyl group, a carboxylgroup, a halogen atom, a cyano group, a nitro group or a hydroxyl group.

Asymmetrical pyrene derivatives shown by the following formula (iii):

wherein Ar⁰⁰⁵ and Ar⁰⁰⁶ are independently an aromatic group having 6 to50 ring carbon atoms,

L⁰⁰¹ and L⁰⁰² are independently a substituted or unsubstituted phenylenegroup, a substituted or unsubstituted naphthalenylene group, asubstituted or unsubstituted fluolenylene group, or a substituted orunsubstituted dibenzosilolylene group,

m is an integer of 0 to 2, n is an integer of 1 to 4, s is an integer of0 to 2, and t is an integer of 0 to 4,

L⁰⁰¹ or Ar⁰⁰⁵ bonds at any one position of 1 to 5 of the pyrene, andL⁰⁰² or Ar⁰⁰⁶ bonds at any one position of 6 to 10 of the pyrene;provided that when n+t is an even number, Ar⁰⁰⁵, Ar⁰⁰⁶, L⁰⁰¹ and L⁰⁰²satisfy the following (1) and (2):

(1) Ar⁰⁰⁵≠Ar⁰⁰⁶ and/or L⁰⁰¹≠L⁰⁰² where ≠ means these substituents aregroups having different structures from each other,

(2) when Ar⁰⁰⁵=Ar⁰⁰⁶ and L⁰⁰¹=L⁰⁰²,

(2-1) m≠s and/or n≠t, or

(2-2) when m=s and n=t,

(2-2-1) when L⁰⁰¹ and L⁰⁰² or pyrene are independently bonded todifferent bonding positions of Ar⁰⁰⁵ and Ar⁰⁰⁶, or (2-2-2) when L⁰⁰¹ andL⁰⁰² or pyrene are bonded to the same position of Ar⁰⁰⁵ and Ar⁰⁰⁶, thepositions of the substitution of L⁰⁰¹ and L⁰⁰² or Ar⁰⁰⁵ and Ar⁰⁰⁶ atpyrene are neither the 1^(st) position and the 6^(th) position, nor the2^(nd) position and the 7^(th) position.

Asymmetrical anthracene shown by the following formula (iv):

wherein A⁰⁰¹ and A⁰⁰² are independently a substituted or unsubstitutedfused aromatic ring group having 10 to 20 ring carbon atoms,

Ar⁰⁰⁷ and Ar⁰⁰⁸ are independently a hydrogen atom or a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms,

R⁰¹¹ to R⁰²⁰ are independently are a hydrogen atom, a substituted orunsubstituted aromatic ring group having 6 to 50 ring carbon atoms, asubstituted or unsubstituted aromatic heterocyclic group having 5 to 50ring atoms, a substituted or unsubstituted alkyl group having 1 to 50carbon atoms, a substituted or unsubstituted cycloalkyl group, asubstituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, asubstituted or unsubstituted aralkyl group having 6 to 50 carbon atoms,a substituted or unsubstituted aryloxy group having 5 to 50 ring atoms,a substituted or unsubstituted arylthio group having 5 to 50 ring atoms,a substituted or unsubstituted alkoxycarbonyl group having 1 to 50carbon atoms, a substituted or unsubstituted silyl group, a carboxylgroup, a halogen atom, a cyano group, a nitro group or a hydroxyl group,and

there may be a plurality of Ar⁰⁰⁷, Ar⁰⁰⁸, R⁰¹⁹ and R⁰²⁰, respectively,and adjacent groups thereof may form a saturated or unsaturated ringstructure,

provided that groups do not symmetrically bond to 9 and 10 positions ofthe central anthracene with respect to X-Y axis.

Anthracene derivative represented by the following formula (v):

wherein R⁰²¹ to R⁰³⁰ are independently a hydrogen atom, an alkyl group,a cycloalkyl group, a substituted or unsubstituted aryl group, an alkoxygroup, an aryloxy group, an alkylamino group, an alkenyl group, anarylamino group or a substituted or unsubstituted heterocyclic group,

a and b are independently an integer of 1 to 5, and when they are two ormore, R⁰²¹s or R⁰²²s may be the same or different, R⁰²¹s or R⁰²²s may bebonded to form a ring, R⁰²³ and R⁰²⁴, R⁰²⁵ and R⁰²⁶, R⁰²⁷ and R⁰²⁸, andR⁰²⁹ and R⁰³⁰ may be bonded to each other to form a ring, and

L⁰⁰³ is a single bond, —O—, —S—, —N(R)— (R is an alkyl group or asubstituted or unsubstituted aryl group), an alkylene group or anarylene group.

Anthracene derivative shown by the following formula (vi):

wherein R⁰³¹ to R⁰⁴⁰ are independently a hydrogen atom, an alkyl group,a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, analkylamino group, an arylamino group or a substituted or unsubstitutedheterocyclic group,

c, d, e and f are independently an integer of 1 to 5, and when they aretwo or more, R⁰³¹s, R⁰³²s, R⁰³⁶s or R⁰³⁷s may be the same or different,R⁰³¹s, R⁰³²s, R⁰³³s or R⁰³⁷s may be bonded to form a ring, and R⁰³³ andR⁰³⁴, and R⁰³⁹ and R⁰⁴⁰ may be bonded to each other to form a ring, and

L⁰⁰⁴ is a single bond, —O—, —S—, —N(R)— (R is an alkyl group or asubstituted or unsubstituted aryl group), an alkylene group or anarylene group.

Spirofluorene derivative represented by the following formula (vii):

wherein A⁰⁰⁵ to A⁰⁰⁸ are independently a substituted or unsubstitutedbiphenyl or a substituted or unsubstituted naphthyl group.Fused ring-containing compounds shown by the following formula (viii):

wherein A⁰¹¹ to A⁰¹³ are independently a substituted or unsubstitutedarylene group having 6 to 50 ring carbon atoms,

A⁰¹⁴ to A⁰¹⁶ are independently a hydrogen atom or a substituted orunsubstituted aryl group having 6 to 50 ring carbon atoms, and

R⁰⁴¹ to R⁰⁴³ are independently a hydrogen atom, alkyl group having 1 to6 carbon atoms, cycloalkyl group having 3 to 6 carbon atoms, alkoxygroup having 1 to 6 carbon atoms, aryloxy group having 5 to 18 carbonatoms, aralkyloxy group having 7 to 18 carbon atoms, arylamino grouphaving 5 to 16 carbon atoms, nitro group, cyano group, ester grouphaving 1 to 6 carbon atoms, or a halogen atom, provided that at leastone of A⁰¹¹ to A⁰¹⁶ is a group having a fused aromatic ring with threeor more rings.

Fluorene compounds shown by the following formula (ix):

wherein R⁰⁵¹ and R⁰⁵² are a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted aralkyl group,a substituted or unsubstituted aryl group, a substituted orunsubstituted heterocyclic group, substituted amino group, cyano group,or a halogen atom,

R⁰⁵¹s or R⁰⁵²s bonded to different fluorene groups may be the same ordifferent, and R⁰⁵¹ and R⁰⁵² bonded to a single fluorene group may bethe same or different,

R⁰⁵³ and R⁰⁵⁴ are independently a hydrogen atom, a substituted orunsubstituted alkyl group, a substituted or unsubstituted aralkyl group,a substituted or unsubstituted aryl group or a substituted orunsubstituted heterocyclic group, R⁰⁵³s or R⁰⁵⁴s bonded to differentfluorene groups may be the same or different, and R⁰⁵³ and R⁰⁵⁴ bondedto a single fluorene group may be the same or different,

Ar⁰¹¹ and Ar⁰¹² are a substituted or unsubstituted fused polycyclicaromatic group with a total number of benzene rings of three or more ora fused polycyclic heterocyclic group which is bonded to the fluorenegroup through substituted or unsubstituted carbon and has a total numberof benzene rings and heterocyclic rings of three or more, provided thatAr⁰¹¹ and Ar⁰¹² may be the same or different and n is an integer of 1 to10.

In the case where phosphorescent dopant is used, specific examples ofthe host compounds include carbazole derivatives, triazole derivatives,oxazole derivatives, oxadiazole derivatives, imidazole derivatives,polyarylalkane derivatives, pyrazoline derivatives, pyrazolonederivatives, phenylenediamine derivatives, arylamine derivatives,amino-substituted calcone derivatives, styryl anthracene derivatives,fluorenone derivatives, hydrazone derivatives, stilbene derivatives andsilazane derivatives; aromatic tertiary amine compounds, styrylaminecompounds, aromatic dimethylidene compounds and porphyrin compounds;anthraquinodimethane derivatives, anthrone derivatives, diphenylquinonederivatives, thiopyrandioxide derivatives, carbodiimide derivatives,fluoreniridenemethane derivatives and distyrylpyrazine derivatives;heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene;phthalocyanine derivatives; various metal complexes represented by metalcomplexes of 8-quinolinol derivatives or metal complexes havingmetalphthalocyanine, benzoxazole or benzothiaole as a ligand;electroconductive macromolecular oligomers such as polysilane compounds,poly(N-vinylcarbazole) derivatives, aniline copolymers, thiopheneoligomers and polythiophene; and polymer compounds such as polythiophenederivatives, polyphenylene derivatives, polyphenylenevinylenederivatives and polyfluorene derivatives. The host compounds may be usedeither singly or in combination of two or more. Specific examplesinclude the following compounds.

In the organic EL device of the invention, the emitting layer maycontain a phosphorescent dopant and/or a fluorescent dopant in additionto the emitting material of the present invention. An emitting layercontaining these dopants may be stacked on an emitting layer containingthe compound of the invention.

A phosphorescent dopant is a compound that can emit light from tripletexcitons. The dopant is not limited so long as it can emit light fromtriplet excitons, but it is preferably a metal complex containing atleast one metal selected from the group of Ir, Ru, Pd, Pt, Os and Re. Aporphyrin metal complex or an ortho-metalated metal complex ispreferable. The phosphorescent compounds can be used individually or asa combination of two or more kinds.

As a porphyrin metal complex, a porphyrin platinum complex ispreferable.

There are various ligands forming an ortho-metalated metal complex.Preferable ligands include compounds having a phenylpyridine skeleton, abipyridyl skeleton or a phenanthroline skeleton, 2-phenylpyridine,7,8-benzoquinoline, 2-(2-thienyl)pyridine, 2-(1-naphthyl)pyridine and2-phenylquinoline derivatives. These ligands may have a substituent, ifnecessary. Ligands to which fluorides, e.g. a trifluoromethyl group,being introduced as a substituent are particularly preferable as a bluedopant. As an auxiliary ligand, preferred are ligands other than theabove-mentioned ligands, such as acetylacetonate and picric acid may becontained.

Specific examples of such metal complex are, not limited to,tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium,tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum,tris(2-phenylpyridine)osmium, tris(2-phenylpyridine)rhenium,octaethylplatinumporphyrin, octaphenylplatinumporphyrin,octaethylpalladiumporphyrin, octaphenylpalladiumporphyrin and the like.A suitable complex is selected according to a required light color,device performance and host material used.

The content of a phosphorescent dopant in an emitting layer is notlimited and can be properly selected according to purposes; for example,it is 0.1 to 70 mass %, preferably 1 to 30 mass %. When the content of aphosphorescent compound is less than 0.1 mass %, emission may be weakand the advantages thereof may not be sufficiently obtained. When thecontent exceeds 70 mass %, the phenomenon called concentration quenchingmay significantly proceed, thereby degrading the device performance.

As for the fluorescent dopant, it is preferable to select a compoundfrom amine-based compounds, aromatic compounds, chelate complexes suchas tris(8-quinolilate)aluminum complexes, coumarin derivatives,tetraphenylbutadiene derivatives, bisstyrylarylene derivatives,oxadiazole derivatives or the like, taking into consideration requiredemission colors. Of these, styrylamine compounds, styryldiaminecompounds, arylamine compounds and aryldiamine compounds are furtherpreferable. Fused polycyclic aromatic compounds which are not an aminecompound are also preferable. These fluorescent dopants may be usedsingly or in combination of two or more.

As the styrylamine compound and the styryldiamine compound, those shownby the following formula (A) are preferable.

wherein Ar¹⁰¹ is a group with a valence of p corresponding to a phenylgroup, a naphthyl group, a biphenyl group, a terphenyl group, astilbenzyl group or a distyrylaryl group, Ar¹⁰² and Ar¹⁰³ areindependently an aromatic hydrocarbon group having 6 to 20 carbon atoms,Ar¹⁰¹, Ar¹⁰² and Ar¹⁰³ may be substituted, one of Ar¹⁰¹ to Ar¹⁰³ issubstituted by a styryl group, further preferably, at least one of Ar¹⁰²and Ar¹⁰³ is substituted by a styryl group, and p is an integer of 1 to4, preferably an integer of 1 to 2.

Here, as the aromatic hydrocarbon group having 6 to 20 carbon atoms, aphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group,a terphenyl group or the like can be given.

As the arylamine compound and the aryldiamine compound, those shown bythe following formula (B) are preferable.

wherein A¹¹¹ is a substituted or unsubstituted aromatic group with avalence of q having 5 to 40 ring carbon atoms, Ar¹¹² and Ar¹¹³ areindependently a substituted or unsubstituted aryl group having 5 to 40ring carbon atoms, and q is an integer of 1 to 4, preferably an integerof 1 to 2.

Examples of the aryl group having 5 to 40 ring carbon atoms include aphenyl group, a naphthyl group, an anthranyl group, a phenanthryl group,a pyrenyl group, a coronenyl group, a biphenyl group, a terphenyl group,a pyrrolyl group, a furanyl group, a thiophenyl group, a benzothiophenylgroup, an oxadiazolyl group, a diphenylanthranyl group, an indolylgroup, a carbazolyl group, a pyridyl group, a benzoquinolyl group, afluoranthenyl group, an acenaphthofluoranthenyl group, a stilbene group,a perylenyl group, a chrysenyl group, a picenyl group, a triphenylenylgroup, a rubicenyl group, a benzanthracenyl group, a phenylanthranylgroup and a bisanthracenyl group. Preferred are a naphthyl group, ananthranyl group, chrysenyl group and a pyrenyl group.

Preferred substituents for the above-mentioned aryl group include analkyl group having 1 to 6 carbon atoms (ethyl, methyl, i-propyl,n-propyl, s-butyl, t-butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, orthe like); an alkoxy group having 1 to 6 carbon atoms (ethoxy, methoxy,i-propoxy, n-propoxy, s-buthoxy, t-buthoxy, penthoxy, hexyloxy,cyclopentoxy, cyclohexyloxy, or the like); an aryl group having 5 to 40ring carbon atoms; an amino group substituted with an aryl group having5 to 40 ring carbon atoms; an ester group with an aryl group having 5 to40 ring carbon atoms; an ester group with an alkyl group having 1 to 6carbon atoms; a silyl group; a cyano group; a nitro group; and a halogenatom.

The emitting layer may contain hole-transporting materials,electron-transporting materials and polymer binders, if necessary.

The thickness of an emitting layer is preferably from 5 to 50 nm, morepreferably from 7 to 50 nm and most preferably from 10 to 50 nm. When itis less than 5 nm, the formation of an emitting layer and the adjustmentof chromaticity may become difficult. When it exceeds 50 nm, the drivingvoltage may increase.

The hole-transporting layer and the hole-injecting layer are layerswhich help the injection of holes into the emitting layer so as totransport holes to an emitting region, and have a large hole mobilityand normally have such a small ionization energy as 5.5 eV or less. Asthe material for the hole-injecting layer and the hole-transportinglayer, a material which transports holes to the emitting layer at alower electrical field is preferable, and the hole mobility thereof ispreferably 10⁻⁴ cm²/V·second or more when an electric field of, e.g.,10⁴ to 10⁶ V/cm is applied.

There are no particular restrictions on the material for thehole-injecting layer and the hole-transporting layer. The material canbe arbitrarily selected from materials which have been widely used as ahole-transporting material of photoconductive materials and knownmaterials used in a hole-injecting layer and a hole-transporting layerof organic EL devices.

In the hole-injecting layer and the hole-transporting layer, an aromaticamine derivative shown by the following formula can be used, forexample.

wherein Ar²¹¹ to Ar²¹³, Ar²²¹ to Ar²²³ and Ar²⁰³ to Ar²⁰⁸ areindependently a substituted or unsubstituted aromatic hydrocarbon grouphaving 6 to 50 ring carbon atoms or a substituted or unsubstitutedaromatic heterocyclic group having 5 to 50 ring atoms, a to c and p to rare independently an integer of 0 to 3, and Ar²⁰³ and Ar²⁰⁴, Ar²⁰⁵ andAr²⁰⁶, or Ar²⁰⁷ and Ar²⁰⁸ may be bonded to each other to form asaturated or unsaturated ring.

Specific examples of the substituted or unsubstituted aromatichydrocarbon groups having 6 to 50 ring carbon atoms include a phenylgroup, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthrylgroup, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group,3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group,1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, and1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2-biphenylyl group,3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group,p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group,m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolylgroup, p-tolyl group, p-t-butylphenyl group, p-(2-phenylpropyl)phenylgroup, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group,4-methyl-1-anthryl group, 4′-methylbiphenylyl group, and4″-t-butyl-p-terphenyl-4-yl group.

Examples of the substituted or unsubstituted aromatic heterocyclic grouphaving 5 to 50 ring atoms include furan, benzofuran, dibenzofuran,thiophene, benzothiophene, dibenzothiophene, carbazole, benzocarbazole,dibenzocarbazole, indole, isoindole, isobenzofuran, pyridine,phthalazine, pyrimidine, pyrazine, triazine, quinoline, isoquinoline,phenanthroline, acridine, 1,7-phenanthroline, 1,8-phenanthroline,1,9-phenanthroline, 2,9-phenanthroline, 2,8-phenanthroline,2,7-phenanthroline, phenazine, phenothiazine, phenoxazine, oxazoline,oxadiazoline, cinnoline, quinoxaline, phthalazine, phenanthridine,indolizine, quinazoline, 1H-indazole, phenoxathiine, thianthrene,furazan, indoline, isoindoline, chromane and isochromane.

Further, the compound shown by the following formula can be used in thehole-injecting layer and the hole-transporting layer.

wherein Ar²³¹ to Ar²³⁴ are independently a substituted or unsubstitutedaromatic hydrocarbon group having 6 to 50 ring carbon atoms, or asubstituted or unsubstituted aromatic heterocyclic group having 5 to 50ring atoms, L is a linking group, which is a single bond, a substitutedor unsubstituted aromatic hydrocarbon group having 6 to 50 ring carbonatoms or a substituted or unsubstituted aromatic heterocyclic grouphaving 5 to 50 ring atoms, x is an integer of 0 to 5, and Ar²³² andAr²³³ may be bonded to each other to form a saturated or unsaturatedring.

As specific examples of the substituted or unsubstituted aromatichydrocarbon group having 6 to 50 ring carbon atoms and substituted orunsubstituted aromatic heterocyclic group having 5 to 50 ring atoms, thesame as those exemplified above can be given.

As specific examples of the material for the hole-injecting layer andthe hole-transporting layer, a triazole derivative, an oxadiazolederivative, an imidazole derivative, a polyarylalkane derivative, apyrazoline derivative, a pyrazolone derivative, a phenylenediaminederivative, an arylamine derivative, an amino-substituted chalkonederivative, an oxazole derivative, a styrylanthracene derivative, afluorenone derivative, a hydrazone derivative, a stilbene derivative, asilazane derivative, an aniline-based copolymer, and conductivehigh-molecular oligomers (in particular, a thiophene oligomer) can begiven.

As the material for the hole-injecting layer and the hole-transportinglayer, although the above-mentioned materials can be used, it ispreferable to use a porphyrin compound, an aromatic tertiary aminecompound and a styrylamine compound. It is particularly preferable touse an aromatic tertiary amine compound.

It is preferable to use a compound having two fused aromatic rings inthe molecule thereof, for example,4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (abbreviated by NPD,hereinafter), and4,4′,4″-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine(abbreviated by MTDATA, hereinafter) wherein three triphenylamine unitsare linked in a star-burst form.

In addition to the above, a nitrogen-containing heterocyclic derivativeshown by the following formula can also be used.

wherein R²⁰¹ to R²⁰⁶ are independently a substituted or unsubstitutedalkyl group, a substituted or unsubstituted aryl group, a substituted orunsubstituted aralkyl group, a substituted or unsubstituted heterocyclicgroup, and R²⁰¹ and R²⁰², R²⁰³ and R²⁰⁴, R²⁰⁵ and R²⁰⁶, R²⁰¹ and R²⁰⁶,R²⁰² and R²⁰³, or R²⁰⁴ and R²⁰⁵ may form a fused ring.

Further, the following compound can also be used.

wherein R²¹¹ to R²¹⁶ are substituents; preferably they are independentlyan electron-attracting group such as a cyano group, a nitro group, asulfonyl group, a carbonyl group, a trifluoromethyl group and a halogen.

Further, an inorganic compound such as p-type Si and p-type SiC can alsobe used as a material for the hole-injecting layer and thehole-transporting layer.

The hole-injecting layer and the hole-transporting layer can be formedfrom the above-mentioned compounds by a known method such as vaporvacuum deposition, spin coating, casting or LB technique. The filmthickness of the hole-injecting layer and the hole-transporting layer isnot particularly limited, and is usually from 5 nm to 5 μm. Thehole-injecting layer and the hole-transporting layer may be a singlelayer made of one or two or more of the above-mentioned materials, ormay be of a structure in which hole-injecting layers andhole-transporting layers made of different compounds are stacked.

The organic semiconductor layer is a layer for helping the injection ofholes or electrons into the emitting layer, and is preferably a layerhaving an electric conductivity of 10⁻¹⁰ S/cm or more. As the materialof such an organic semiconductor layer, electroconductive oligomers suchas thiophene-containing oligomers or arylamine-containing oligomers andelectroconductive dendrimers such as arylamine-containing dendrimers maybe used.

The electron-injecting layer and the electron-transporting layer arelayers which assist injection of electrons into the emitting layer andtransport electrons to the emitting region, and exhibit a high electronmobility. The adhesion-improving layer is a kind of theelectron-injecting layer which is made of a material exhibitingparticularly good adhesion to the cathode.

The thickness of the electron-transporting layer is arbitrarily selectedin the range of 5 nm to 5 μm. When the electron-transporting layer has athick thickness, it is preferable that the electron mobility be 10⁻⁵cm²/Vs or more at an applied electric field of 10⁴ to 10⁶ V/cm in orderto prevent an increase in voltage.

The material used in the electron-injecting layer and theelectron-transporting layer is preferably a metal complex of8-hydroxyquinoline or a derivative thereof, or an oxadiazole derivative.Specific examples of the metal complex of 8-hydroxyquinoline orderivative thereof include metal chelate oxynoid compounds containing achelate of oxine (generally, 8-quinolinol or 8-hydroxyquinoline), e.g.tris(8-quinolinolato)aluminum.

As examples of the oxadiazole derivative an electron-transportingcompound shown by the following formula can be given.

wherein Ar³⁰¹, Ar³⁰², Ar³⁰³, Ar³⁰⁵, R³⁰⁶ and Ar³⁰⁹ are independently asubstituted or unsubstituted aryl group, and Ar³⁰⁴, Ar³⁰⁷ and Ar³⁰⁸ areindependently a substituted or unsubstituted arylene group.

As examples of the aryl group, a phenyl group, a biphenyl group, ananthranyl group, a perylenyl group, and a pyrenyl group can be given. Asexamples of the arylene group, a phenylene group, a naphthylene group, abiphenylene group, an anthranylene group, a perylenylene group, apyrenylene group, and the like can be given. As the substituent, analkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10carbon atoms, a cyano group, and the like can be given. Theelectron-transporting compound is preferably one from which a thin filmcan be formed.

The following compounds can be given as specific examples of theelectron-transporting compound.

(Me is methyl and tBu is t-Butyl.)

Furthermore, as materials used for the electron-injecting layer andelectron-transporting layer, the compounds represented by the followingformulas (E) to (J) may be used.

Nitrogen-containing heterocyclic derivatives shown by the formulas (E)and (F):wherein Ar³¹¹ to Ar³¹³ are independently a nitrogen atom or a carbonatom,

Ar³¹¹ is a substituted or unsubstituted aryl group having 6 to 60 ringcarbon atoms or a substituted or unsubstituted heteroaryl group having 3to 60 ring carbon atoms, Ar^(311′) is an arylene group having 6 to 60ring carbon atoms or a substituted or unsubstituted heteroarylene grouphaving 3 to 60 ring carbon atoms, and Ar³¹² is a hydrogen atom, asubstituted or unsubstituted aryl group having 6 to 60 ring carbonatoms, a substituted or unsubstituted heteroaryl group having 3 to 60ring carbon atoms, a substituted or unsubstituted alkyl group having 1to 20 carbon atoms, or a substituted or unsubstituted alkoxy grouphaving 1 to 20 carbon atoms, provided that one of Ar³¹¹ and Ar³¹² is asubstituted or unsubstituted fused ring group having 10 to 60 ringcarbon atoms or a substituted or unsubstituted monohetero fused ringgroup having 3 to 60 ring carbon atoms,

L³¹¹, L³¹² and L³¹³ are independently a single bond, a substituted orunsubstituted arylene group having 6 to 60 ring carbon atoms, asubstituted or unsubstituted heteroarylene group having 3 to 60 ringcarbon atoms, or a substituted or unsubstituted fluorenylene group,

R and R³¹¹ are independently a hydrogen atom, a substituted orunsubstituted aryl group having 6 to 60 ring carbon atoms, a substitutedor unsubstituted heteroaryl group having 3 to 60 ring carbon atoms, asubstituted or unsubstituted alkyl group having 1 to 20 carbon atoms, ora substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms,

n is an integer of 0 to 5, and

when n is two or more, plural Rs may be the same or different, andadjacent Rs may be bonded to each other to form a carbocyclic aliphaticring or a carbocyclic aromatic ring.

HAr-L³¹⁴-Ar³²¹—Ar³²²  (G)

Nitrogen-containing heterocyclic derivatives shown by the formula (G):wherein HAr is a nitrogen-containing heterocyclic ring having 3 to 40carbon atoms, which may have a substituent, L³¹⁴ is a single bond, anarylene group having 6 to 60 carbon atoms, which may have a substituent,an heteroarylene group having 3 to 60 carbon atoms, which may have asubstituent, or a fluorenylene group which may have a substituent, Ar³²¹is a divalent aromatic hydrocarbon group having 6 to 60 carbon atoms,which may have a substituent, and Ar³²² is a an aryl group having 6 to60 carbon atoms, which may have a substituent or a heteroaryl grouphaving 3 to 60 carbon atoms, which may have a substituent.

Silacyclopentadiene derivatives shown by the formula (H) wherein X³⁰¹and Y³⁰¹ are independently a saturated or unsaturated hydrocarbon grouphaving 1 to 6 carbon atoms, an alkoxy group, an alkenyloxy group, analkynyloxy group, a hydroxyl group, a substituted or unsubstituted arylgroup, or a substituted or unsubstituted hetero ring, or X and Y arebonded to form a saturated or unsaturated ring, and R³⁰¹ to R³⁰⁴ areindependently hydrogen, halogen, an alkyl group, an alkoxy group, anaryloxy group, a perfluoroalkyl group, a perfluoroalkoxy group, an aminogroup, an alkylcarbonyl group, an arylcarbonyl group, an alkoxycarbonylgroup, an aryloxycarbonyl group, an azo group, an alkylcarbonyloxygroup, an arylcarbonyloxy group, an alkoxycarbonyloxy group, anaryloxycarbonyloxy group, a sulfinyl group, a sulfonyl group, a sulfanylgroup, a silyl group, a carbamoyl group, an aryl group, a heterocyclicgroup, an alkenyl group, an alkynyl group, a nitro group, a formylgroup, a nitroso group, a formyloxy group, an isocyano group, a cyanategroup, an isocyanate group, a thiocyanate group, an isothiocyanategroup, or a cyano group. These groups may be substituted and adjacentgroups may form a substituted or unsubstituted fused ring.

Borane derivatives shown by the formula (I) wherein R³²¹ to R³²⁸ andZ³²² are independently a hydrogen atom, a saturated or unsaturatedhydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group,a substituted amino group, a substituted boryl group, an alkoxy group,or an aryloxy group, X³³², Y³⁰², and Z³²¹ are independently a saturatedor unsaturated hydrocarbon group, an aromatic hydrocarbon group, aheterocyclic group, a substituted amino group, an alkoxy group, or anaryloxy group, Z³²¹ and Z³²² may be bonded to form a fused ring, and nis an integer of 1 to 3, provided that when n or (3−n) is two or more,R³²¹ to R³²⁸, X³⁰², Y³⁰², Z³²² and Z³²¹ may be the same or different,provided that compounds where n is 1, X³⁰², Y³⁰², and R³²² are methylgroups, and R³²⁸ is a hydrogen atom or a substituted boryl group, andcompounds where n is 3 and Z³²¹ is a methyl group are excluded.

Gallium complexes shown by the formula (J) wherein Q³⁰¹ and Q³⁰² areindependently ligands represented by the following formula (K) and L³¹⁵is a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, a substituted or unsubstituted heterocyclicgroup, —OR(R is a hydrogen atom, a substituted or unsubstituted alkylgroup, a substituted or unsubstituted cycloalkyl group, a substituted orunsubstituted aryl group, or a substituted or unsubstituted heterocyclicgroup) or a ligand represented by —O—Ga-Q³⁰³(Q³⁰⁴) wherein Q³⁰³ and Q³⁰⁴are the same as Q³⁰¹ and Q³⁰².

wherein rings A³⁰¹ and A³⁰² are independently a 6-membered aryl ringstructure which may have a substituent and they are fused to each other.

The metal complexes have the strong nature of an n-type semiconductorand large ability of injecting electrons. Further, the energy generatedat the time of forming a complex is small so that a metal is thenstrongly bonded to ligands in the complex formed and the fluorescentquantum efficiency becomes large as the emitting material.

Specific examples of the substituents for the rings A³⁰¹ and A³⁰²forming the ligand of the formula (K) include halogen atoms such aschlorine, bromine, iodine, and fluorine, substituted or unsubstitutedalkyl groups such as a methyl group, ethyl group, propyl group, butylgroup, sec-butyl group, tert-butyl group, pentyl group, hexyl group,heptyl group, octyl group, stearyl group, and trichloromethyl group,substituted or unsubstituted aryl groups such as a phenyl group,naphthyl group, biphenyl group, anthranyl group, phenanthryl group,fluorenyl group, pyrenyl group, 3-methylphenyl group, 3-methoxyphenylgroup, 3-fluorophenyl group, 3-trichloromethylphenyl group,3-trifluoromethylphenyl group, and 3-nitrophenyl group, substituted orunsubstituted alkoxy groups such as a methoxy group, n-butoxy group,tert-butoxy group, trichloromethoxy group, trifluoroethoxy group,pentafluoropropoxy group, 2,2,3,3-tetrafluoropropoxy group,1,1,1,3,3,3-hexafluoro-2-propoxy group, and 6-(perfluoroethyl)hexyloxygroup, substituted or unsubstituted aryloxy groups such as a phenoxygroup, p-nitrophenoxy group, p-tert-butylphenoxy group, 3-fluorophenoxygroup, pentafluorophenyl group, and 3-trifluoromethylphenoxy group,substituted or unsubstituted alkylthio groups such as a methylthiogroup, ethylthio group, tert-butylthio group, hexylthio group, octylthiogroup, and trifluoromethylthio group, substituted or unsubstitutedarylthio groups such as a phenylthio group, p-nitrophenylthio group,p-tert-butylphenylthio group, 3-fluorophenylthio group,pentafluorophenylthio group, and 3-trifluoromethylphenylthio group, acyano group, a nitro group, an amino group, mono- or di-substitutedamino groups such as a methylamino group, diethylamino group, ethylaminogroup, diethylamino group, dipropylamino group, dibutylamino group, anddiphenylamino group, acylamino groups such as a bis(acetoxymethyl)aminogroup, bis(acetoxyethyl)amino group, bis(acetoxypropyl)amino group, andbis(acetoxybutyl)amino group, a hydroxyl group, a siloxy group, an acylgroup, substituted or unsubstituted carbamoyl groups such as a carbamoylgroup, methylcarbamoyl group, dimethylcarbamoyl group, ethylcarbamoylgroup, diethylcarbamoyl group, propylcarbamoyl group, butylcarbamoylgroup, and phenylcarbamoyl group, a carboxylic acid group, a sulfonicacid group, an imide group, cycloalkyl groups such as a cyclopentanegroup and cyclohexyl group, heterocyclic groups such as a pyridinygroup, pyrazinyl group, pyrimidinyl group, pyridazinyl group, triazinylgroup, indolinyl group, quinolinyl group, acridinyl group, pyrrolidinylgroup, dioxanyl group, piperidinyl group, morpholidinyl group,piperazinyl group, carbazolyl group, furanyl group, thiophenyl group,oxazolyl group, oxadiazolyl group, benzoxazolyl group, thiazolyl group,thiadiazolyl group, benzothiazolyl group, triazolyl group, imidazolylgroup, and benzimidazolyl group. The above substituents may be bonded toform a further six-membered aryl ring or heterocyclic ring.

A preferred embodiment of the organic EL device is a device containing areducing dopant in an electron-transferring region or in an interfacialregion between a cathode and an organic layer. The reducing dopant isdefined as a substance which can reduce an electron-transferringcompound. Accordingly, various substances which have given reducingproperties can be used. For example, at least one substance can bepreferably used which is selected from the group consisting of alkalimetals, alkaline earth metals, rare earth metals, alkali metal oxides,alkali metal halides, alkaline earth metal oxides, alkaline earth metalhalides, rare earth metal oxides, rare earth metal halides, alkali metalcarbonates, alkaline earth metal carbonates, rare earth metalcarbonates, alkali metal organic complexes, alkaline earth metal organiccomplexes, and rare earth metal organic complexes.

More specific examples of the preferred reducing dopants include atleast one alkali metal selected from the group consisting of Na (workfunction: 2.36 eV), K (work function: 2.28 eV), Rb (work function: 2.16eV) and Cs (work function: 1.95 eV), and at least one alkaline earthmetal selected from the group consisting of Ca (work function: 2.9 eV),Sr (work function: 2.0 to 2.5 eV), and Ba (work function: 2.52 eV).Metals having a work function of 2.9 eV or less are particularlypreferred. Among these, a more preferable reducing dopant is at leastone alkali metal selected from the group consisting of K, Rb and Cs.Even more preferable is Rb or Cs. Most preferable is Cs. These alkalimetals are particularly high in reducing ability. Thus, the addition ofa relatively small amount thereof to an electron-injecting zone improvesthe luminance of the organic EL device and make the lifetime thereoflong. As a reducing agent having a work function of 2.9 eV or less,combinations of two or more alkali metals are preferable, particularlycombinations including Cs, such as Cs and Na, Cs and K, Cs and Rb, orCs, Na and K are preferable. The combination containing Cs makes itpossible to exhibit the reducing ability efficiently. The luminance ofthe organic EL device can be improved and the lifetime thereof can bemade long by the addition thereof to its electron-injecting zone.

An electron-injecting layer made of an insulator or a semiconductor mayfurther be provided between a cathode and an organic layer. By formingthe electron-injecting layer, a current leakage can be effectivelyprevented and electron-injecting properties can be improved. If theelectron-injecting layer is an insulating thin film, more uniformed thinfilm can be formed whereby pixel defects such as a dark spot aredecreased.

As the insulator, at least one metal compound selected from the groupconsisting of alkali metal calcogenides, alkaline earth metalcalcogenides, halides of alkali metals and halides of alkaline earthmetals can be preferably used. When the electron-injecting layer isformed of the alkali metal calcogenide or the like, the injection ofelectrons can be preferably further improved. Specifically preferablealkali metal calcogenides include Li₂O, K₂O, Na₂S, Na₂Se and Na₂O andpreferable alkaline earth metal calcogenides include CaO, BaO, SrO, BeO,BaS and CaSe. Preferable halides of alkali metals include LiF, NaF, KF,CsF, LiCl, KCl and NaCl. Preferable halides of alkaline earth metalsinclude fluorides such as CaF₂, BaF₂, SrF₂, MgF₂ and BeF₂ and the otherhalides corresponding to the fluorides.

Semiconductors forming an electron-injecting layer include one orcombinations of two or more of oxides, nitrides, and oxidized nitridescontaining at least one element of Ba, Ca, Sr, Yb, Al, Ga, In, Li, Na,Cd, Mg, Si, Ta, Sb and Zn. An inorganic compound forming anelectron-injecting layer is preferably a microcrystalline or amorphousinsulating thin film.

For the cathode, the following may be used: an electrode substance madeof a metal, an alloy or an electroconductive compound, or a mixturethereof which has a small work function (for example, 4 eV or less).Specific examples of the electrode substance include sodium,sodium-potassium alloy, magnesium, lithium, cesium, magnesium/silveralloy, aluminum/aluminum oxide, Al/Li₂O, Al/LiO, Al/LiF,aluminum/lithium alloy, indium, and rare earth metals.

The cathode is formed from these electrode materials by vapordeposition, sputtering or the like.

In the case where emission from the emitting layer is outcoupled throughthe cathode, it is preferred to make the transmittance of the cathode tothe emission larger than 10%. The sheet resistance of the cathode ispreferably several hundreds Ω/□ or less, and the film thickness thereofis usually from 10 nm to 1 μm, preferably from 50 to 200 nm.

Generally, in the organic EL device, pixel defects based on leakage or ashort circuit are easily generated since an electric field is applied tothe super thin film. In order to prevent this, it is preferred to insertan insulating thin layer between the pair of electrodes.

Examples of the material used in the insulating layer include aluminumoxide, lithium fluoride, lithium oxide, cesium fluoride, cesium oxide,magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride,aluminum nitride, titanium oxide, silicon oxide, germanium oxide,silicon nitride, boron nitride, molybdenum oxide, ruthenium oxide, andvanadium oxide. A mixture or laminate thereof may be used.

As for the method for fabricating the organic EL device, it can befabricated by forming necessary layers sequentially from the anode usingthe materials and the method as mentioned above, and finally forming thecathode. The organic EL device can be fabricated in the order reverse tothe above, i.e., the order from the cathode to the anode.

An example of the fabrication of the organic EL device will be describedbelow which has a structure wherein the following are successivelyformed on a transparent substrate: anode/hole-injecting layer/emittinglayer/electron-injecting layer/cathode.

At first, a thin film formed of an anode material is formed on atransparent substrate by vapor deposition or sputtering to form ananode.

Next, a hole-injecting layer is formed on this anode. As describedabove, the hole-injecting layer can be formed by vacuum deposition, spincoating, casting, LB technique, or some other method. Vacuum depositionis preferred since a homogenous film is easily obtained and pinholes arenot easily generated. In the case where the hole-injecting layer isformed by vacuum deposition, conditions for the deposition varydepending upon a compound used (a material for the hole-injectinglayer), a desired structure of the hole-injecting layer, and others. Ingeneral, the conditions are preferably selected from the following:deposition source temperature of 50 to 450° C., vacuum degree of 10⁻⁷ to10⁻³ Torr, vapor deposition rate of 0.01 to 50 nm/second, and substratetemperature of −50 to 300° C.

Next, an emitting layer is formed on the hole-injecting layer. Theemitting layer can also be formed by making a luminescent material intoa thin film by vacuum vapor deposition, sputtering, spin coating,casting or some other method. Vacuum vapor deposition is preferred sincea homogenous film is easily obtained and pinholes are not easilygenerated. In the case where the emitting layer is formed by vacuumvapor deposition, conditions for the deposition, which vary depending ona compound used, can be generally selected from conditions similar tothose for the hole-injecting layer.

Next, an electron-injecting layer is formed on the emitting layer. Likethe hole-injecting layer and the emitting layer, the layer is preferablyformed by vacuum vapor deposition because a homogenous film is required.Conditions for the deposition can be selected from conditions similar tothose for the hole-injecting layer and the emitting layer.

Lastly, a cathode is stacked thereon to obtain an organic EL device. Thecathode can be formed by vapor deposition or sputtering. However, vaporvacuum deposition is preferred in order to protect underlying organiclayers from being damaged when the cathode film is formed.

For the organic EL device fabrication described above, it is preferredthat the formation from the anode to the cathode is continuously carriedout, using only one vacuuming operation.

The method for forming each of the layers in the organic EL device isnot particularly limited. An organic thin film layer containing thecompound of the invention can be formed by a known method such as vacuumvapor deposition, molecular beam epitaxy (MBE), or an applying coatingmethod using a solution in which the compound is dissolved in a solvent,such as dipping, spin coating, casting, bar coating, or roll coating.

EXAMPLES

Examples will be explained below. However, the invention is not limitedby these examples.

Organic EL devices were evaluated as follows:

(1) Initial performance: Luminance and CIE1931 chromaticity coordinateat 10 mA/cm² were measured by a luminance meter (SpectroradiometerCS-1000 manufactured by Minorta Co., Ltd.) and evaluated.(2) Life time: The organic EL device is driven at a constant currentwith an initial luminance of 1000 cd/m², and life time thereof wasevaluated with the half-life of luminance and variation in chromaticity.

Example 1 (1) Synthesis of Benzanthracene Compound

To a 1 litter four-necked flask, 20 g (80.9 mmol) of 2-bromodibenzofuranwas placed, and argon substitution was conducted by repeating threetimes decrease of pressure in the system and returning it to theoriginal pressure with argon gas. Then, 120 mL of dried tetrahydrofuranwas added thereto and completely dissolved with stirring. Subsequently,the solution was cooled to about −65° C. with a dry ice/acetone bath,and 52 mL (80.9 mmol) of a solution of 1.57M n-butyllithium in hexanewas dropwise added thereto over about 20 minutes. The reaction wascontinued at −65° C. for 2 hours, and then, a solution of 9.5 g (36.8mmol) of benzanthraquinone in 300 mL of dried tetrahydrofuran wasdropwise added thereto over one hour. Subsequently, the reaction wascontinued at −65° C. for about 2 hours, then, the reaction mixture washeated to room temperature and the reaction was continued for 2 hours.Next day, 100 mL of a 1N hydrochloride aqueous solution was addedthereto to terminate the reaction. Subsequently, the reaction solutionwas extracted by a mixture of ethyl acetate and water, and Na₂SO₄ wasadded to the organic phase. The organic phase was stirred for one hour,and dried, followed by concentration. To the resulting solids, 50 mL ofa solution of hexane/ethyl acetate=1/1 was added, and the precipitatewas collected by filtration, followed by vacuum drying (Intermediate 1:yield amount: 14.9 g, yield: 55.7%, HPLC purity: 97.8%).

To a 1 litter flask, 14.9 g (20.5 mmol) of the intermediate 1, 8.5 g(51.4 mmol) of potassium iodide and 2.7 g (25.6 mmol) of NaPH₂O₂.H₂Owere placed, the atmosphere in the system was substituted by argon gas,and then, 300 mL of acetic acid was added. Subsequently, the mixture washeated with an oil bath to react at 80° C. for 8 hours. Next day,precipitate was collected by filtration, and washed with acetic acid,methanol and water, followed by vacuum drying to obtain H-1 (yieldamount: 9.04 g, yield: 78.7%).

Subsequently, a decreasing treatment of halogen content was conducted inaccordance with JP-A-2007-77078 (yield amount: 6.43 g, HPLC purity:99.9%, glass transition temperature: 159.5° C.).

(2) Fabrication of Organic EL Device

A glass substrate of 25 mm by 75 mm by 1.1 mm thick with an ITOtransparent electrode (anode) (GEOMATEC CO., LTD.) was subjected toultrasonic cleaning with isopropyl alcohol for 5 minutes, and thencleaned with ultraviolet rays and ozone for 30 minutes. The cleanedglass substrate with transparent electrode lines was mounted in asubstrate holder of a vapor deposition apparatus. First, as a holeinjecting layer, a 60 nm-thick film of the following compound A-1 wasformed on the surface where the transparent electrode lines were formedso as to cover the transparent electrode. Subsequent to the filmformation of A-1 film, a 20 nm-thick film of the following compound A-2was formed on the A-1 film, as a hole transporting layer.

A 40 nm-thick film was formed on the A-2 film using compound H-1 of theinvention and a diamine derivative D-1 in a film thickness ratio of40:2, to obtain a blue-light emitting layer. H-1 acts as a host and D-1acts as a dopant.

On this film, a 20 nm-thick film was formed as an electron transportinglayer using the following compound Alq by deposition, followed byformation of 1 nm-thick LIE film. A 150 nm-thick metal Al film wasformed on the LiF film by deposition to form a metal cathode, whereby anorganic EL device was obtained.

For the organic EL devices fabricated, initial performances(chromaticity and luminous efficiency) and half life (time) wereevaluated. The results are shown in Table 1. From Table 1, it isunderstood that a blue light emission having high purity could beobtained.

Examples 2 to 30

A device was fabricated and evaluated in the same manner as in Example 1except that H-1 and/or D-1 were replaced with the compounds indicated inTable 1. The results are shown in Table 1.

Here, synthesis of benzanthracene compounds were conducted according tothe synthesis routes (2) and (3).

FA and FA′: aryl groups such as fused rings

Comparative Examples 1 to 3 (1) Synthesis of Benzanthracene Compound

Synthesis was conducted according to a conventional method in the samemanner as in Example 1.

(2) Fabrication of Organic EL Device

A device was fabricated in the same manner as in Example 1 except thatH-1 and D-1 were replaced with the compounds indicated in Table 1. Theresults are shown in Table 1.

TABLE 1 Luminous Life time Emitting Material Chromaticity efficiency(hours) (Host) (Dopant) (CIEx, CIEy) (cd/A) @1000 cd/m² Ex. 1 H-1 D-1(0.15, 0.20) 7.8 8,500 Ex. 2 H-1 D-2 (0.16, 0.19) 7.4 8,000 Ex. 3 H-1D-3 (0.15, 0.17) 7.0 7,800 Ex. 4 H-2 D-1 (0.15, 0.19) 7.5 8,200 Ex. 5H-2 D-2 (0.16, 0.19) 7.3 7,900 Ex. 6 H-2 D-3 (0.15, 0.17) 7.0 8,200 Ex.7 H-3 D-1 (0.15, 0.22) 7.5 6,900 Ex. 8 H-3 D-2 (0.16, 0.23) 7.3 7,200Ex. 9 H-3 D-3 (0.15, 0.21) 7.2 7,100 Ex. 10 H-4 D-1 (0.15, 0.19) 7.98,800 Ex. 11 H-4 D-2 (0.16, 0.18) 7.8 9,200 Ex. 12 H-4 D-3 (0.15, 0.17)7.2 7,900 Ex. 13 H-5 D-1 (0.15, 0.19) 8.1 8,500 Ex. 14 H-5 D-2 (0.16,0.19) 7.8 8,300 Ex. 15 H-5 D-3 (0.15, 0.18) 7.4 8,100 Ex. 16 H-6 D-1(0.15, 0.19) 7.8 9,000 Ex. 17 H-6 D-2 (0.16, 0.19) 7.4 8,400 Ex. 18 H-6D-3 (0.15, 0.17) 7.3 8,200 Ex. 19 H-7 D-1 (0.15, 0.21) 7.6 7,900 Ex. 20H-7 D-2 (0.16, 0.20) 7.4 7,600 Ex. 21 H-7 D-3 (0.15, 0.17) 7.0 7,800 Ex.22 H-8 D-1 (0.15, 0.21) 7.9 8,300 Ex. 23 H-8 D-2 (0.16, 0.20) 7.6 8,100Ex. 24 H-8 D-3 (0.15, 0.17) 7.4 7,800 Ex. 25 H-9 D-1 (0.15, 0.19) 7.88,200 Ex. 26 H-9 D-2 (0.16, 0.19) 7.5 8,300 Ex. 27 H-9 D-3 (0.15, 0.17)7.0 8,100 Ex. 28 H-10 D-1 (0.15, 0.21) 7.6 8,300 Ex. 29 H-10 D-2 (0.16,0.20) 7.4 8,100 Ex. 30 H-10 D-3 (0.15, 0.17) 7.0 7,800 Comp. Ex. 1 h-1D-2 (0.20, 0.29) 5.9 3,000 Comp. Ex. 2 h-2 D-2 (0.21, 0.35) 5.5 2,800Comp. Ex. 3 h-3 D-2 (0.20, 0.31) 5.3 2,000

As is understood from Table 1, when the compound of the invention isused as the emitting material, blue light emission having high puritycan be obtained, and the half life of the device is longer than that ofthe device using the conventional compound.

INDUSTRIAL APPLICABILITY

The benzabthracene compound of the invention can be used in an organicEL device.

The organic EL device of the invention can be suitably used as a lightsource such as a planar emitting body and backlight of a display, adisplay part of a portable phone, a PDA, a car navigator, or aninstrument panel of an automobile, an illuminator, and the like.

The documents described in the specification are incorporated herein byreference in its entirety.

1. A compound having the following structure as at least a part:

wherein FA and FA′ are independently a substituted or unsubstitutedhydrocarbon aromatic ring or hetero atom-containing aromatic ring, andat least one of FA and FA′ is the hetero atom-containing aromatic ring.2. The compound according to claim 1, which has one of the followingstructures as at least a part thereof:

wherein X is oxygen, sulfur or N—R wherein R is a hydrocarbon group, andFA and FA′ are independently a substituted or unsubstituted hydrocarbonaromatic ring or hetero atom-containing aromatic ring.
 3. An emittingmaterial comprising the compound according to claim
 1. 4. An organicelectroluminescence device which comprises: an anode, a cathode, and oneor more organic thin film layers including an emitting layer, which arebetween the anode and the cathode, wherein at least one layer of theorganic thin film layers comprises the compound according to claim
 1. 5.The organic electroluminescence device according to claim 4, wherein thelayer comprising the compound further comprises at least one of aphosphorescent dopant and a fluorescent dopant.
 6. The organicelectroluminescence device according to claim 5, wherein the fluorescentdopant is at least one of arylamine compounds and styrylamine compounds.7. The organic electroluminescence device according to claim 5, whereinthe phosphorescent dopant is a metal complex.